A new poll shows a dramatic reshaping in the race for the Republican nomination for governor as the 50-point lead former eBay CEO Meg Whitman held over state Insurance Commissioner Steve Poizner in March has closed to single digits.

The survey, by the Public Policy Institute of California, shows Whitman leading Poizner 38 percent to 29 percent among likely voters in the June 8 Republican primary, with 30 percent undecided. That’s down from 61 percent to 11 percent, with 24 percent undecided, two months ago.

Whitman, a billionaire who so far has put $68 million of her own money into her campaign, galloped off to a seemingly insurmountable lead early in the year as she waged a sustained, saturation television advertising campaign and had the airwaves to herself.

Poizner, another former Silicon Valley high-tech entrepreneur who’s independently wealthy but can’t come close to matching his opponent dollar for dollar, held his fire until the past several weeks.

But once he started spending the $24 million in personal money he has pumped into his campaign, he began closing the gap quickly.

The barrage of claims and counterclaims on the airwaves — over immigration, ethics and who’s the real conservative — has apparently added to voter confusion and created the unusual dynamic of the undecided vote increasing rather than decreasing as primary election day draws nearer.

The Republican U.S. Senate primary is also very close, with former Hewlett-Packard CEO Carly Fiorina and former Rep. Tom Campbell statistically tied as they were in March. The poll showed Fiorina preferred by 25 percent and Campbell 23 percent, which is within the poll’s margin of error of 5 percentage points.

The third Republican in the race, Assemblyman Chuck DeVore of Irvine, saw his support double from 8 percent in March to 16 percent.

On the Democratic side, presumptive gubernatorial nominee Jerry Brown, the current attorney general, and U.S. Sen. Barbara Boxer face no major opposition for their respective nominations.

“This election is very much in flux,” said Mark Baldassare, president and CEO of the public-policy institute. “Voters are alienated. Republicans are struggling to figure out what to do about it and what their party stands for. The Democrats — with their candidates unchallenged — aren’t going through this soul-searching.”

Looking ahead to potential matchups in the general election, Brown leads Whitman 42 percent to 37 percent among likely voters and Poizner 45 percent to 32 percent. In March, Whitman held a hypothetical lead over Brown of 44 percent to 39 percent.

The poll also registered strong support for Proposition 14, the June ballot measure that would change primary elections from the current system of party nominations to one where the top two vote-getters regardless of party would advance to the general election.

Support for Proposition 14 has grown by 4 points among likely voters since March to 60 percent, with 27 percent opposed and 13 percent undecided.